JP6977338B2 - LED module - Google Patents

Description

The present invention relates to an LED module.

In recent years, various LED display devices using an LED backlight as a light source, such as an in-vehicle display device, have rapidly become widespread.

In these display devices, in order to configure a backlight using an LED element as a light source, a circuit board for an LED element in which a metal wiring portion is usually formed on a support substrate (in the present specification, "for an LED element". "Substrate") is used. A laminate in which LED elements are mounted on such a substrate (in the present specification, the laminate having such a configuration is referred to as an "LED module") constitutes the backlight of various LED display devices. It is widely used as a light source module.

The LED backlight includes an edge light type backlight in which the LED element is arranged on the side of the display surface, and a direct type backlight in which the LED element as a light source is arranged on the back side of the display surface to form a surface light source. It is roughly divided into. Of these, especially in the direct type LED backlight, in order to use the light emitted from the LED element more efficiently, the light leaking to the back side of the LED backlight is reflected to the display screen side. The material is arranged around the LED element mounting area (see Patent Document 1).

Here, in order to more efficiently utilize the light emitted from the LED element, the peripheral edge of the opening of the reflective material formed surrounding the LED element and the individual surrounded by the opening. It is desirable to minimize the distance (gap width) between the LED element and the outer edge of the LED element as much as possible.

However, there are certain limits to the processing accuracy of the position and size of the opening of the reflective material and the position accuracy of mounting the LED element. Specifically, it was extremely difficult to make the above-mentioned gap width about 0.1 mm or less.

On the other hand, since the LED backlight incorporating the LED module mounts a large number of LED elements by soldering, it is essential to inspect the lighting of the final product before shipping. However, for example, when the above gap width is narrowed to the limit value in the processing technology of about 0.1 mm, the bonding state of the solder portion located below the reflective material cannot be visually observed, so that the light is turned on. If there was even one defective element, it was necessary to destructively peel off the reflective material and other laminated members and re-inspect the bonded state of the soldered portion. Since this destructive inspection leads to an increase in work load and a decrease in productivity, in order to avoid this, even if the optical characteristics are intentionally sacrificed, emphasis is placed on the ease of lighting inspection, and the above gap width is intentionally described. In some cases, it was designed to leave a width of about 0.6 mm.

Japanese Unexamined Patent Publication No. 2010-15583

The present invention has been made in view of the above circumstances, and is an LED module used for constructing a direct-type backlight, which has high brightness as a light source and lighting inspection at the time of product shipment. It is an object of the present invention to provide an LED module that has both ease and ease.

As a result of diligent research, the present inventors have made it a form in which a side wall surrounding the LED element is formed so as to surround the LED element and stand up at a specific portion of the peripheral edge of the opening formed in the reflective material arranged in the LED module. As a structure in which the inner surface of the side wall surrounding the LED element is brought into contact with the side surface of the LED element, continuity at the joint portion of the LED element is minimized while minimizing the gap width between each LED element and the peripheral edge of the opening of the reflective material. We have found that the above problems can be solved by providing a structure that leaves a gap width that allows the state of the solder portion to be visually recognized on the periphery of the LED element in a specific direction with respect to the direction, and have completed the present invention. .. Specifically, the present invention provides the following.

(1) Covers the LED element substrate in which the metal wiring portion is formed on the surface of the support substrate, the plurality of LED elements mounted on the metal wiring portion, and the region excluding the mounting region of the LED element. An LED module comprising a reflective material laminated on the LED element substrate, wherein the LED element is a part of the metal wiring portion and is formed at a position where the LED element is separated from each other and faces each other. It is mounted via a solder portion on a mounting portion composed of a pair of conductive plates, and the reflective material is made of a flexible resin sheet, and an opening is formed at a position corresponding to the mounting region. A part of the resin sheet is bent toward the top of the LED element at a portion of the peripheral edge of the opening that is parallel or substantially parallel to the conduction direction between the pair of conductive plates. By standing up, the LED element surrounding side wall is formed, and at least a part of the inner surface including the top of the LED element surrounding side wall is in contact with the side surface of the LED element, and among the peripheral edges of the opening. The LED element surrounding side wall is not formed in the portion parallel or substantially parallel to the direction orthogonal to the conduction direction, and the peripheral edge of the opening is viewed from the light emitting surface side of the LED module. An LED module in which a solder portion for fixing the LED element to the metal wiring portion is visibly exposed in the vicinity of a portion where the side wall surrounding the LED element is not formed.

In the invention of (1), only the portion of the peripheral edge of the opening of the reflective material arranged on the substrate for the LED element, which is parallel to or substantially parallel to the conduction direction of the mounted LED element, is located in the opening. A side wall surrounding the LED element is formed so as to surround the LED element, and at least a part of the inner surface including the top of the side wall surrounding the LED element is attached to the side surface of each LED element. As a result, in the LED module used to configure the direct type backlight, the gap width between each LED element and the peripheral edge of the opening of the reflective material is reduced, and the utilization efficiency of the light emitted from the LED element is reduced. Can be enhanced. On the other hand, a minimum gap width is intentionally left in a portion other than the above on the peripheral edge of the opening, and the LED element 2 is connected to the metal wiring portion 13 (conductive plate 131, in a plan view from the light emitting surface side of the LED module 10). The solder portion 17 fixed to 132) is visibly exposed. As a result, while enjoying the above-mentioned effect of improving the utilization efficiency of the light emitted from the LED element, the conduction state of the solder portion is not destroyed in any part of the LED module including the reflective material and other members. It can be an LED module that can be inspected, that is, an LED module that has excellent optical characteristics and can be inspected for non-destructive lighting.

Here, the "LED element mounting area" in the present specification is an area consisting of a portion of the LED element substrate that is a junction to the metal wiring portion of the LED element and a peripheral portion thereof, and is a region for mounting the LED element. It refers to the area directly under the space that is at least required as an optical path to the outside of the light emitted from the LED element.

(2) The LED module according to (1), wherein the bending stress of the resin sheet forming the reflective material based on ASTM-D790 is 10 MPa or more and 40 MPa or less.

In the invention of (2), the bending stress of the material resin sheet of the reflective material in the invention of (1) is limited to a predetermined range. As a result, a part of the flexible resin sheet constituting the reflective material can be easily bent and made to stand up. Moreover, it is possible to easily maintain the preferred form of the side wall surrounding the LED element that stands up.

(3) An adhesive layer is formed on the back surface of the reflective material, and the reflective material is attached to the LED element substrate and the LED element via the adhesive layer, (1) or ( The LED module according to 2).

In the invention of (3), an adhesive layer is formed on the inner surface of the reflective material, and by sticking through this layer, the position of the reflective material is displaced on the substrate for the LED element and the LED on the side wall surrounding the LED element. The configuration is such that peeling from the side surface of the element can be prevented more reliably. Thereby, the effect of improving the brightness of the direct type LED backlight using the LED module (1) or (2) can be stably maintained for a longer period of time.

(4) The LED element surrounding side wall rises substantially perpendicular to the surface of the LED element substrate at the peripheral edge of the opening, and substantially the entire inner surface of the LED element surrounding side wall is the LED element. The LED module according to any one of (1) to (3), which is in contact with the side surface of the above.

In the invention of (4), the contact surface between the inner surface of the side wall surrounding the LED element in the LED module according to any one of (1) to (3) and the side surface of the LED element is maximized. It is possible to further enhance the stability of the attachment or attachment of the two-part agent at this interface.

(5) Only a part of the back surface of the LED element surrounding side wall near the top is in contact with a part of the side surface of the LED element near the top, and the LED element surrounding side wall is the opening. The LED module according to any one of (1) to (4), which rises in a tapered shape in which the opening diameter narrows from the peripheral edge of the LED element toward the top of the LED element.

In the invention of (5), the direction in which the reflective surface formed by the side wall surrounding the LED element in the LED module according to any one of (1) to (3) can be reflected from the vicinity of the light source toward the distance of the light source. Formed towards. As a result, the diffusion of light is promoted toward the outside when each LED element is centered, and the uniformity of brightness over the entire light emitting surface of the LED module according to any one of (1) to (3) is achieved. Can be improved.

(6) The LED module according to (5), wherein the side wall surrounding the LED element has a concave curved surface shape that is convex toward the support substrate side.

In the invention of (6), the reflective surface formed by the side wall surrounding the LED element in the LED module according to (5) is a reflective surface having a concave curved surface shape. As a result, in the LED backlight provided with the LED module according to (5), the light having higher brightness, which is reflected at a position closer to the LED element, can be reflected toward a farther distance. As a result, it is possible to improve the uniformity of the brightness of the surface light source as a whole while maintaining the higher brightness.

(7) The LED module according to any one of (1) to (6), wherein the support substrate is a flexible resin film, so that the substrate for an LED element is a flexible substrate.

In the invention of (7), the substrate for the LED element constituting the LED module according to any one of (1) to (6) is not a rigid rigid substrate but a so-called flexible substrate. According to this, the LED backlight that enjoys the effect of the LED module according to any one of (1) to (6) and has excellent shape followability to the installation surface of various shapes. Can be configured.

(8) An LED display device including a backlight comprising the LED module according to any one of (1) to (7).

In the invention of (8), the LED display device is provided with an LED backlight configured by using the LED module according to any one of (1) to (7). According to this, it is possible to obtain an LED display device provided with a high-luminance LED backlight by the effect of any of the LED modules (1) to (7).

(9) The lighting inspection method for an LED module according to any one of (1) to (7), which is visibly exposed in the vicinity of the peripheral edge of the opening by a plan view from the light emitting surface side of the LED module. A method for inspecting lighting of an LED module, comprising a step of inspecting the continuity state of the soldered portion without damaging any part of the LED module.

In the invention of (9), by configuring the LED modules as described in any one of (1) to (7), the effect of improving the utilization efficiency of the emitted light that can be played by these LED modules can be obtained. While enjoying it, in the lighting inspection performed before shipping the product, the continuity state of the solder part that is visibly exposed near the peripheral edge of the opening by the plan view from the light emitting surface side of the LED module is inspected by non-destructive inspection. be able to.

According to the present invention, there is provided an LED module used for forming a direct-type backlight, which has both high brightness as a light source and ease of lighting inspection at the time of product shipment. can do.

It is a top view schematically showing an example of the LED module of this invention. FIG. 1 is a drawing in which the reflective material in the LED module of FIG. 1 is removed, and is provided for explaining the form of the mounting portion of the LED element in the LED module of the present invention. It is a cross-sectional enlarged view which shows the cross section of the AA part of FIG. 1 schematically, and is the drawing which provides the explanation of the layer structure of the LED module of this invention. It is a drawing which provides the explanation of the layer structure in the other embodiment of the LED module of this invention. It is a drawing which provides the explanation of the layer structure in the other embodiment of the LED module of this invention. It is a partially enlarged plan view of the reflective material which can be preferably used for the LED module of this invention. It is a partially enlarged plan view of the peripheral part of the LED mounting area in another embodiment of the LED module of this invention. FIG. 7 is a partially enlarged front view and a side view of the peripheral portion of the LED mounting region in the embodiment shown in FIG. 7 of the LED module of the present invention. It is a drawing which provides the explanation of the manufacturing method of the LED module of this invention. It is a perspective view schematically showing the outline of the layer structure of the LED display device made by using the LED module of this invention.

Hereinafter, embodiments of the LED module and the LED display device of the present invention will be described. The present invention is not limited to the following embodiments, and can be carried out with appropriate modifications within the scope of the object of the present invention.

<LED module>
As shown in FIGS. 1 to 3, the LED module 10 of the present invention is a light source module in which a surface light source is configured by mounting a plurality of LED elements 2 in a matrix on a substrate 1 for an LED element. This light source module can be preferably used mainly as a light source for a direct type LED backlight.

The LED element substrate 1 constituting the LED module 10 is flexible in such a manner that a metal wiring portion 13 is formed on the surface of the support substrate 11 and covers other portions excluding the mounting area of the plurality of LED elements 2. A reflective material 15 made of a resin sheet having a property is laminated on a substrate 1 for an LED element. Further, as shown in FIG. 3, the LED module 10 is preferably formed with an insulating protective film 14 covering the metal wiring portion 13, and in this case, the reflective material 15 is an insulating protective film. Placed on 14.

Then, in the "LED element mounting area" of the LED module 10, the LED element 2 is mounted on the metal wiring portion 13 via the solder portion 17, and in this state, among the peripheral edges of the opening of the reflective material 15. , The LED element surrounding side wall 151 that is subordinate to the peripheral edge of the opening of the reflective material 15 is formed only in the portion parallel or substantially parallel to the conduction direction between the pair of conductive plates 131 and 132, and this LED element is formed. The inner surface of the surrounding side wall 151 is in contact with the side surface of the LED element 2.

In a conventional LED module, as described above, a gap width of about 0.1 mm or more is unavoidable between the peripheral edge of the opening of the reflective material and the side surface of the LED element located in the opening. Were present. However, in the LED module 10 of the present invention, the gap width can be set to 0 by contacting at least a part of the inner surface including the top of the LED element surrounding side wall 151 with the side surface of the LED element 2. can. Here, the term "adhesive" as used herein refers to all aspects in which the objects to be adhered are in contact with each other without gaps, and the structure of the adhesion is desired in the overall configuration of the article (for example, LED module). A mode having stability is sufficient, and a mode of contact in which a chemical bonding structure by an adhesive or an adhesive does not necessarily exist is also included. For example, due to the elasticity of the resin sheet constituting the reflective material, a very small part from the top of the inner surface of the LED element surrounding side wall 151, or between the top surface and the inner surface of the LED element surrounding side wall 151. It is also one aspect of the above-mentioned "contact" when the contact state with the LED element 2 is maintained in the mode in which the corners are in line contact.

However, as shown in FIG. 3, the adhesion between the inner surface of the LED element surrounding side wall 151 of the reflective material 15 and the side surface of the LED element 2 located in the opening is the adhesive layer 16 having appropriate adhesiveness. It is more preferable that the mode is mediated by. Details of the reflective material 15 having the adhesive layer 16 will be described later.

On the other hand, in the "LED element mounting area" of the LED module 10, as shown in FIG. 7, the LED element surrounding side wall 151 is formed in the peripheral edge of the opening in the plan view from the light emitting surface side of the LED module 10. The LED element 2 is fixed to the metal wiring portion 13 (conductive plates 131, 132) in the vicinity of the portion that is not present, that is, the portion of the peripheral edge of the opening that is parallel or substantially parallel to the direction orthogonal to the conduction direction. The solder portion 17 is visibly exposed. With such a configuration, while enjoying the above-mentioned effect of improving the utilization efficiency of the light emitted from the LED element 2, the conduction state of the solder portion is controlled by the LED module 10 including the reflective material 15 and other members. It can be an LED module that can inspect any part without destroying it, that is, an LED module that can be inspected for lighting by non-destructive inspection.

The LED module 10 having the configuration described above can be preferably used as a light source module constituting a direct-type LED backlight in the LED display device 100 shown in FIG. 10 and other various types of LED display devices in general. ..

When the LED module 10 is used to form a direct-type LED backlight, a transmissive reflector and a diffuser plate (both of which are shown in the figure) are located at positions separated from the light emitting surface of the LED element 2 by a predetermined distance. It is common to further arrange optical members such as (1).

[LED element substrate]
Next, the details of the LED element substrate 1 constituting the LED module 10 will be described. As shown in FIGS. 1 to 3, the LED element substrate 1 which is a wiring board on which the LED element 2 is mounted has a conductive metal wiring portion 13 made of a metal foil or the like on the surface of a support substrate 11 made of a resin film or the like. However, they are laminated via the adhesive layer 12. An insulating protective film 14 is formed on the support substrate 11 and the metal wiring portion 13 in a region other than the “LED element mounting region”. Then, the reflective material 15 is laminated on the outermost surface of the LED module 10 on the light emitting surface side so as to cover the region on the support substrate 11 and the metal wiring portion 13 excluding the “LED element mounting region”.

(Support board)
As the support substrate 11, various substrate materials conventionally used as a support substrate for a substrate for an LED element can be appropriately used. However, this substrate material is preferably a flexible resin film. In addition, in the present specification, "having flexibility" means that "the radius of curvature can be bent to at least 1 m or less, preferably 50 cm, more preferably 30 cm, still more preferably 10 cm, and particularly preferably 5 cm. ".

When a flexible resin film is used as the material of the support substrate 11, the film is required to have high heat resistance and insulating properties. As such a resin film, a resin film made of polyimide (PI), polyethylene naphthalate (PEN), or the like, which is excellent in heat resistance, dimensional stability during heating, mechanical strength, and durability, can be preferably used. Among them, those made of polyethylene naphthalate (PEN) whose heat resistance and dimensional stability have been improved by subjecting them to heat resistance improving treatment such as annealing treatment can be particularly preferably used. Further, a resin film made of polyethylene terephthalate (PET) whose flame retardancy has been improved by adding a flame retardant inorganic filler or the like can also be preferably used as a material for the support substrate 11.

When the substrate material forming the support substrate 11 is a resin film made of a thermoplastic resin, the heat shrinkage start temperature is 100 ° C. or higher, or the temperature becomes 100 ° C. or higher by the above annealing treatment or the like. As described above, it is preferable to use one having improved heat resistance. Normally, the temperature around the LED element may reach a temperature of about 90 ° C. due to the heat generated from the LED element. From this point of view, it is preferable that the resin film forming the support substrate has heat resistance equal to or higher than the above temperature. The "heat shrinkage start temperature" in the present specification means that a sample film made of a thermoplastic resin to be measured is set in a TMA device, a load of 1 g is applied, and the temperature rises to 120 ° C. at a temperature rise rate of 2 ° C./min. After warming, the amount of shrinkage (% display) at that time is measured, and from the graph that outputs this data and records the temperature and amount of shrinkage, the temperature away from the 0% baseline due to shrinkage is read, and that temperature is heat-shrinked. It is the starting temperature.

The support substrate 11 is required to be a resin having a high insulating property that can impart the insulating property required for the LED element substrate 1 when integrated as the LED module 10. In general, the support substrate 11 preferably has a volume resistivity of 10 ¹⁴ Ω · cm or more, and more preferably 10 ¹⁸ Ω · cm or more.

The thickness of the support substrate 11 is not particularly limited. However, the thickness of the support substrate 11 should be 12 μm or more and 500 μm or less from the viewpoint of not becoming a bottleneck as a heat dissipation path, having heat resistance and insulating properties, and balancing manufacturing costs. Is preferable, and more preferably 20 μm or more and 250 μm or less. Further, from the viewpoint of maintaining good productivity in the case of manufacturing by the roll-to-roll method, the above thickness range is preferable.

(Adhesive layer)
In the LED element substrate 1, the metal wiring portion 13 is preferably formed on the surface of the support substrate 11 by a dry laminating method via an adhesive layer 12. As the adhesive forming the adhesive layer 12, a known resin-based adhesive can be appropriately used. Among these resin adhesives, acrylic-based, urethane-based, polycarbonate-based, or epoxy-based adhesives can be particularly preferably used.

(Metal wiring part)
As shown in FIGS. 2 and 3, the metal wiring portion 13 is a wiring pattern formed by a conductive base material made of various metal foils or the like on the surface of a support substrate 11 constituting the substrate 1 for an LED element.

The metal wiring portion 13 has a form in which the basic unit of mounting shown in FIG. 3, that is, the basic unit composed of a combination of a pair of conductive plates 131 and 132 is repeatedly formed in the X direction and the Y direction orthogonal to the basic unit. Is preferable. By mounting a plurality of LED elements 2 in such a wiring pattern in a matrix, it is possible to form a surface light source of a direct type LED backlight.

As shown in FIG. 3, each LED element 2 is a part of a metal wiring portion 13, and is mounted on a mounting portion composed of a pair of conductive plates 131 and 132 formed at positions facing each other apart from each other. It is mounted via the solder portion 17.

In addition to the portion that is the basic unit of the above-mentioned mounting, the metal wiring portion 13 includes a connector wiring that connects conductive plates arranged in different rows or columns in a matrix-like arrangement, and a terminal portion of the row or column. The LED module 10 is configured to include a terminal for making an electrical connection between the LED module 10 and an external power source or the like. In the LED element substrate 1, the degree of freedom in designing the arrangement of the conductive plates 131 and 132, the connector wiring, and the terminals constituting the metal wiring portion 13 and their combinations is high, and the form of conduction of a large number of LED elements 2 is in series. It is possible to connect either in parallel or in parallel, and the wiring can be an optimum combination of both connections according to the characteristics required for the LED module 10 after mounting.

The thermal conductivity λ of the metal constituting the metal wiring portion 13 is preferably 200 W / (m · K) or more and 500 W / (m · K) or less, and 300 W / (m · K) or more and 500 W / (m · K) or less. More preferred. The electrical resistivity R of the metal constituting the metal wiring portion 13 ^{is preferably 3.00 × 10 -8} Ωm or less, and more preferably 2.50 × 10 ^{-8 Ωm or less.} Here, for the measurement of the thermal conductivity λ, for example, a thermal conductivity meter QTM-500 manufactured by Kyoto Denshi Kogyo Co., Ltd. can be used, and for the measurement of the electrical resistivity R, for example, a 6517B type electrometer manufactured by Caseley Co., Ltd. can be used. Can be used. According to this, for example, in the case of copper, the thermal conductivity λ is 403 W / (m · K), and the electrical resistivity R is 1.55 × 10 ⁻⁸ Ωm. This makes it possible to achieve both heat dissipation and electrical conductivity. More specifically, since the heat dissipation from the LED element is stable and the increase in electrical resistance can be prevented, the variation in light emission between the LEDs is reduced, stable light emission of the LED is possible, and the life of the LED is extended. .. Further, since deterioration of peripheral members such as a substrate due to heat can be prevented, the product life of the image display device itself incorporating the substrate for LED elements as a backlight can be extended.

Examples of the metal constituting the metal wiring portion 13 include aluminum, gold, silver, and copper. The thickness of the metal wiring portion 13 may be appropriately set according to the magnitude of the withstand current required for the LED element substrate 1, and is not particularly limited, but an example thereof is a thickness of 10 μm to 50 μm. From the viewpoint of improving heat dissipation, the thickness of the metal wiring portion 13 is preferably 10 μm or more. Further, if the thickness of the metal layer does not reach the above lower limit value, the influence of heat shrinkage of the support substrate 11 is large, and the warp after the processing tends to be large during the solder reflow processing. Therefore, from this viewpoint as well, the thickness of the metal wiring portion 13 is large. Is preferably 10 μm or more. On the other hand, when the same thickness is 50 μm or less, sufficient flexibility of the substrate for the LED element can be maintained, and deterioration of handleability due to an increase in weight can be prevented.

(Insulating protective film)
As the resin composition for forming the insulating protective film 14, various conventionally known thermosetting inks can be used. The thermosetting ink preferably has a thermosetting temperature of about 120 ° C. or lower. Specifically, an insulating ink containing a polyester resin, an epoxy resin, an epoxy resin, a phenol resin, an epoxy acrylate resin, a silicone resin, a fluororesin, or the like as a base resin can be preferably used. Can be mentioned as a typical example of. Among these, the polyester-based thermosetting insulating ink is particularly preferable as a material for forming the insulating protective film 14 of the substrate 1 for an LED element because it is excellent in flexibility. The "heat-curing temperature" in the present specification is calculated by measuring and calculating the temperature at the rising position of the heat-curing reaction when the heat-curing resin to be measured is heated, and the temperature is defined as the heat-curing temperature. ..

Further, by adding a white pigment to the heat-curable ink forming the insulating protective film 14 and making it a white ink, the insulating protective film 14 can be made into a light reflecting layer having a light reflection function. can. As the white pigment used in this case, an inorganic white pigment such as titanium dioxide can be mentioned as an example of a preferable pigment.

(Reflective material)
The reflective material 15 is a reflective member having high reflectivity mainly to light in the visible light wavelength region, and can form the LED element surrounding side wall 151 on the peripheral edge of the opening as described in detail below. It may be made of a flexible resin sheet. For the purpose of improving the light emitting ability of the LED backlight using the LED module 10, such a reflective material 15 covers the area excluding the area for mounting the LED element and covers the outermost surface of the LED module 10 on the light emitting surface side. Stacked.

As shown in FIGS. 1 and 3, the reflective material 15 is formed with an opening at a position corresponding to the LED element mounting region. The formation of the opening in the resin sheet constituting the reflective material 15 can be performed by various conventionally known drilling processes such as punching process and laser process.

When the LED element 2 has a rectangular parallelepiped shape as shown in FIG. 3, the shape of the opening is preferably a rectangular shape corresponding to the outer peripheral shape. The LED module of the present invention can be particularly preferably applied when the outer peripheral shape of the side surface of the LED element is such a rectangular shape. However, when the LED element 2 has a cylindrical shape, it is possible to enjoy the same effect by making the shape of the opening circular corresponding to this, and an LED module having such a shape is also available. It is within the scope of the present invention. When the outer peripheral shape of the side surface of the LED element is circular or elliptical in this way, the shape of the opening is changed to a shape substantially similar to each of these shapes, and further, a resin sheet having a large elasticity is formed. As in the case of the LED module 10 to which the rectangular LED element 2 is mounted, by forming a part of the side wall by the stretching allowance of the sheet or by making an appropriate notch around the opening. The above-mentioned gap width can be eliminated to improve the utilization efficiency of the light emitted from the LED element. Hereinafter, the details of the reflector 15 and the LED element surrounding side wall 151 when the LED element 2 has a rectangular parallelepiped shape as shown in FIG. 3, that is, when the shape of the opening is rectangular will be described.

As shown in FIG. 3, the reflective material 15 is formed with an LED element surrounding side wall 151 at the peripheral edge of each opening. The LED element surrounding side wall 151 is formed by partially bending a part of the resin sheet constituting the reflective material 15 toward the top of the LED element 2 mounted on the opening and supporting the LED element.

In the LED module 10, the LED element surrounding side wall 151 is in contact with the side surface of the LED element 2. As a result, the LED module 10 has the peripheral edge of the opening of the reflective material 15 and the LED element 2 in the portion where the LED element surrounding side wall 151 is formed, which causes a decrease in the utilization efficiency of the light emitted from the LED element 2. It is a structure that eliminates the gap width between and.

As a form of the LED element surrounding side wall 151, for example, as shown in FIG. 4, a form that follows substantially perpendicular to the surface of the LED element substrate 1 is a preferred embodiment of the LED element surrounding side wall 151. It can be exemplified. In this embodiment, substantially the entire surface of the inner surface of the LED element surrounding side wall 151 is brought into contact with the side surface of the LED element 2, and the stability of contact between the inner surface of the LED element surrounding side wall 151 and the side surface of the LED element 2 is stable. Can be made higher.

As a form of the LED element surrounding side wall 151, for example, as shown in FIG. 5, a form in which the width of the opening narrows from the peripheral edge of the opening toward the top of the LED element 2 is formed in a tapered shape. It can be exemplified as another preferred embodiment of 151. In this form, only a part of the inner surface of the LED element surrounding side wall 151 near the top side is in contact with a part of the side surface of the LED element near the top side. In this form, it is possible to promote the diffusion of the light emitted from the individual LED elements 2 and improve the uniformity of the brightness in the entire light emitting surface of the LED module 10.

Further, when the LED element surrounding side wall 151 has a tapered shape as described above, as shown in FIG. 5, a space E is formed between the solder portion 17 and the reflective material 15 or the adhesive layer 16. As a result, it is possible to avoid contact between the solder portion 17 and the reflective material 15, which become hot due to heat generated when the LED element 2 is lit, and prevent deterioration of the reflective material due to high heat.

Further, as shown in FIG. 5, the LED element surrounding side wall 151 may further have a concave reflecting portion 152 having a concave curved surface shape that is convex toward the support substrate 11. According to the LED element surrounding side wall 151 having such a form, it is possible to reflect the light having higher brightness, which is reflected at a position closer to the LED element, toward a farther distance. As a result, in the LED module 10, it is possible to improve the uniformity of the brightness of the surface light source as a whole while maintaining the higher brightness.

Regarding the gap G (FIG. 4) in height, which is the difference between the vertical position of the top of the LED element surrounding side wall 151 and the vertical position of the top of the LED element 2 in contact with the vertical position. The optical characteristics for the purpose of improving the brightness, the size of which is preferably 0.1 mm or less, and most preferably 0.

Further, as shown in FIG. 6, the reflective material 15 may have a plurality of notches 153 formed on the peripheral edge of the opening to facilitate the formation of the LED element surrounding side wall 151. By bending the resin sheet constituting the reflective material 15 along the line including the end point portion of the notch 153, it becomes easier to form the LED element surrounding side wall 151 that follows the position surrounding the LED mounting area. Moreover, these can be formed while maintaining higher position and shape accuracy.

The resin sheet constituting the reflective material 15 may be a member having reflectivity for reflecting the light emitted from the LED element 2 and guiding the light emitted from the LED element 2 in a predetermined direction in terms of optical characteristics. In this respect, more specifically, the reflective material 15 preferably has a light reflectance of 95% or more, and more preferably 97% or more, of light having a wavelength of 450 nm or more and 650 nm or less. Further, in order to improve the uniformity of luminance in the entire light emitting surface of the LED module, it is more preferable that the LED module has a reflecting surface having a high diffuse reflectance. As an index of a preferable diffuse reflectance, a resin sheet having a reflective surface having a specular reflectance of 30% or less can be mentioned as an example of a preferable resin sheet.

Here, the definitions of the light reflectance, the diffuse reflectance, and the specular reflectance in the present specification are as follows.
The reflectance at 450 nm or more and 650 nm or less was measured, and the numerical values at each wavelength were averaged to obtain the reflectance and the diffuse reflectance. Further, the normal reflectance was calculated from the reflectance and the diffuse reflectance at each wavelength by the following equation (1), and the numerical values at each wavelength were averaged to obtain the normal reflectance. Since it is difficult to accurately measure the absolute reflectance, the relative reflectance with that of the comparative standard sample is usually used for the above reflectance. In the present invention, barium sulfate is used as a comparative standard sample. For the reflectance in the present invention, an integrating sphere attachment device (for example, an integrating sphere unit ISN-723) is attached to a spectrophotometer (for example, JASCO Corporation V-670DS), barium sulfate is used as a standard plate, and the standard plate is 100. It is the measured value of the relative reflectance in%.

Specular reflectance (%) = Reflectance (%) -Diffuse reflectance (%) ... (1)

When the above-mentioned light reflectance of the reflective material 15 is 95% or more, most of the light emitted from the LED element 2 that leaks to the side surface or the back surface side of the LED module 10 is reflected to the display screen side. Can be done. As a result, the light emitted from the LED element 2 can be used extremely efficiently.

The specular reflectance of the reflective material 15 calculated by the above method is preferably 30% or less, and more preferably 1% or more and 25% or less. By increasing the ratio of the diffuse reflectance to the reflectance of the light as much as possible, the light emitted from the LED element 2 is uniformly diffused over the entire screen of the LED display device 100 to reduce the uneven brightness and improve the image quality. be able to. From the viewpoint of improving the diffuse reflectance, the smaller the specular reflectance is, the more preferable it is, but it is not preferable from the viewpoint of cost because it requires a special material and a manufacturing method such as a filler having an extremely narrow particle size distribution. If the regular reflectance exceeds 30%, the ratio of the diffuse reflectance decreases and the halation due to light reflection becomes too strong, so that the display screen feels dazzling, which is not preferable.

In the LED module 10, in addition to the above-mentioned requirements for optical characteristics, the reflective material 15 is also required to have a specific bending stress as a mechanical strength. A part of the resin sheet constituting the reflective material 15 can be easily bent to form the LED element surrounding side wall 151, and further, the shape of the side wall can be easily maintained. Is preferable. In order to satisfy this requirement, the resin sheet forming the reflective material 15 is preferably a resin sheet having a bending stress of 10 MPa or more and 40 MPa or less based on ASTM-D790. When this bending stress is less than 10 MPa, it is difficult to stably maintain the standing contact of the LED element surrounding side wall 151 and the contact with the side surface of the LED element 2 particularly when the adhesive layer 16 is not present. Further, even when the adhesive layer 16 is present, this bending stress bends and deforms the reflective material 15 to form the LED element surrounding side wall 151, and retains its preferable shape. Therefore, it is preferably 10 MPa or more. On the other hand, when this bending stress exceeds 40 MPa, it is not preferable in that it becomes difficult to make the reflective material 15 stand upright to form the LED element surrounding side wall 151 having a desired shape.

As an example of a resin sheet for making the reflective material 15 satisfy each of the above requirements relating to optical properties and mechanical strength, for example, a foamed resin film using an olefin resin, a foamed type white polyester, and silver. Examples include vapor-deposited polyester. Any of these resin sheets can be appropriately selected according to the form and application of the final product LED display device and its required specifications. For example, when the LED module 10 is used as a backlight of an in-vehicle LED display device that is relatively small but has high brightness and is required to follow the shape of various installation surfaces, the above-mentioned Among them, a foamed resin film using an olefin resin can be preferably used. In addition, since LED display devices for automobiles are also required to have flame retardancy, olefin-based foaming resins such as polypropylene-based resin-based foamed resins having autolysis are also used for this purpose. It is extremely suitable as a material for display devices for LEDs.

As an example of a foamed resin sheet that can be particularly preferably used as the resin sheet constituting the reflective material 15, a resin sheet having the same composition as the "foamed resin film" disclosed in International Publication No. 2007/132828 is preferable. It can be given as a concrete example. As disclosed in the above document, this foamed resin sheet can be obtained by stretching and molding a resin composition containing an olefin resin as a base resin and a filler. Hereinafter, the details of this foamed resin sheet will be described.

Among the olefin resins, the base resin of the foamed resin sheet constituting the reflective material 15 is particularly preferably a polypropylene resin such as a propylene homopolymer or a propylene-ethylene copolymer. In addition, ethylene-based resins such as high-density polyethylene can also be used. These can also be used by mixing two or more kinds. Of these, it is more preferable to use a propylene-based resin from the viewpoints of water resistance, water repellency, chemical resistance, production cost, and the like.

As the above-mentioned propylene-based resin, a propylene homopolymer or propylene as a main component and an α-olefin such as ethylene, 1-butene, 1-hexene, 1-hexene, 4-methyl-1-pentene and the like are co-weighted. Coalescence can be used. The stereoregularity is not particularly limited, and isotactic or syndiotactic and those exhibiting various degrees of stereoregularity can be used. Further, the copolymer may be a binary system, a ternary system, a quaternary system, a random copolymer, or a block copolymer.

It is preferable that the foamed resin sheet constituting the reflective material 15 contains 20% by mass or more and 75% by mass or less of the filler. When the total amount of the filler contained in the foamed resin sheet is 75% by mass or less, the strength of the foamed resin sheet is high, and it is easy to obtain a material that can sufficiently withstand practical use. When the filler content is 20% by mass or more, sufficient pores can be easily formed, and preferable diffuse reflectance can be easily obtained.

As the filler contained in the foamed resin sheet, various inorganic fillers or organic fillers can be used. Examples of the inorganic filler include heavy calcium carbonate, precipitated calcium carbonate, calcined clay, talc, titanium oxide, barium sulfate, aluminum sulfate, silica, zinc oxide, magnesium oxide, diatomaceous soil and the like.

According to the reflective material 15 made of the foamed resin sheet, the light reflectance is 95% or more and the normal reflectance is 30% by setting the thickness of the reflective material 15 in the range of 50 μm or more and 200 μm or less. The following optical characteristics can be imparted to the reflective material 15. Further, if necessary, by further thickening the reflective material 15, it is possible to impart a higher reflectance to the reflective material 15.

Further, by setting the thickness of the reflective material 15 made of the foamed resin sheet to the range of 50 μm or more and 200 μm or less as described above, the bending stress of the reflective material 15 based on ASTM-D790 is optimized to the range of 10 MPa or more and 40 MPa or less. can do.

The above-mentioned foamed resin sheet has a larger surface friction than a general non-foamed resin sheet. Therefore, when such a foamed resin sheet is used as the reflective material 15, the interface where the back surface of the reflective material 15 and the side surface of the LED element 2 are in contact with each other is compared with the case where a non-foamed resin sheet having a smooth surface is used. Even when the adhesive layer does not exist or the contact area is very small, the elasticity of the resin sheet and the frictional force make it easy to maintain the contact state in a preferable shape.

The reflective material 15 may have an adhesive layer 16 formed on an inner surface when laminated on the LED module 10, that is, on the back surface side opposite to the surface exposed on the outermost surface of the LED module. preferable. By configuring the reflective material 15 to be attached to the surface of the LED element substrate 1 via the adhesive layer 16, the reflective material 15 is finally fixed in the module by another fixing means. It is possible to prevent misalignment at the stage of. Further, the LED element surrounding side wall 151, which is a part of the reflective material 15, is similarly attached to the side surface of the LED element 2 via the adhesive layer 16. It is possible to enhance the long-term stability of the brightness improving effect of the LED module 10 by increasing the intensity of the LED module 10.

The adhesive layer 16 is preferably formed by using a double-sided adhesive tape having heat resistance enough to withstand a high temperature of about 100 ° C. For example, by forming the adhesive layer 16 by using an acrylic adhesive-based double-sided adhesive tape having such heat resistance, the LED element surrounding side wall 151 is formed from the side surface of the LED element 2 due to the high temperature emitted from the LED element 2. It is possible to prevent the peeling. As the double-sided adhesive tape having such heat resistance, for example, a commercially available "heat-resistant double-sided adhesive tape: No. 5919ML (manufactured by Nitto Denko KK)" or the like can be used.

[LED element]
The LED element 2 is a light emitting element that utilizes light emission at a PN junction where a P-type semiconductor and an N-type semiconductor are joined. A structure in which P-type electrodes and N-type electrodes are provided on the upper and lower surfaces of the device and a structure in which both P-type and N-type electrodes are provided on one surface of the device have been proposed. The LED element 2 having any structure can be used for the LED module 10 of the present invention, but it is particularly preferable to use an LED element having a structure in which both P-type and N-type electrodes are provided on one side of the element. can.

For LED elements in order to uniformly diffuse the directional light emitted from each LED element as a light source over the entire light emitting surface of the backlight in order to display a high-quality image without unevenness in the LED module 10. In the substrate 1, a light diffusion type lens (not shown) may be attached to each LED element 2. The light diffusion type lens is a light diffusion type lens that diffuses the light emitted from the LED element 2, and is, for example, an aspherical lens. For example, it can be formed of a transparent resin material such as polymethyl methacrylate (PMMA), polycarbonate (PC), epoxy resin (EP), or transparent glass. For example, an optical member capable of exhibiting a desired light diffusion effect, including a conventionally known lens member disclosed in Japanese Patent Application Laid-Open No. 2013-12417, can be appropriately used.

[Solder part]
In the LED element substrate 1, the metal wiring portion 13 and the LED element 2 are joined via the solder portion 17. The soldering method can be roughly classified into either a reflow method or a laser method.

<Manufacturing method of substrate for LED element>
The LED element substrate 1 can be manufactured by an etching step, which is one of the conventionally known methods for manufacturing an electronic substrate, and a reflector mounting step peculiar to the present invention.

[Etching process]
A metal wiring portion 13 such as a copper foil used as a material for the metal wiring portion 13 is laminated on the surface of the support substrate 11 which has been subjected to a heat resistant treatment such as an annealing treatment as needed to obtain a laminated body as a material. As the laminating method, a method of adhering a metal foil to the surface of the support substrate 11 with an adhesive, a plating method directly on the surface of the support substrate 11, or a vapor phase film forming method (sputtering, ion plating, electron beam deposition, etc.) A method of vapor-depositing the metal wiring portion 13 by vacuum vapor deposition, chemical vapor deposition, etc.) can be mentioned. From the viewpoint of cost and productivity, a method of adhering the metal foil to the surface of the support substrate 11 with a urethane-based adhesive is advantageous.

Next, an etching mask patterned in a shape required for the metal wiring portion 13 is formed on the surface of the metal foil of the laminated body. The etching mask is provided so that the wiring pattern forming portion of the metal foil, which will be the metal wiring portion 13 in the future, is prevented from being corroded by the etching solution. The method for forming the etching mask is not particularly limited, and for example, the etching mask may be formed on the surface of the laminated film by exposing the photoresist or dry film through the photomask and then developing it, or an inkjet printer or the like. An etching mask may be formed on the surface of the laminated film by the printing technique of.

Next, the metal foil in the portion not covered by the etching mask is removed by the dipping solution. As a result, the portion of the metal foil other than the portion that becomes the metal wiring portion 13 is removed.

Finally, an alkaline stripper is used to remove the etching mask. As a result, the etching mask is removed from the surface of the metal wiring portion 13.
(Etching process)
A metal wiring portion 13 such as a copper foil used as a material for the metal wiring portion 13 is laminated on the surface of the support substrate 11 to obtain a laminate used as a material for the LED element substrate 1. As the laminating method, a method of adhering a metal foil to the surface of the support substrate 11 with an adhesive, a plating method directly on the surface of the support substrate 11, or a vapor phase film forming method (sputtering, ion plating, electron beam deposition, etc.) A method of vapor-depositing the metal wiring portion 13 by vacuum vapor deposition, chemical vapor deposition, etc.) can be mentioned. From the viewpoint of cost and productivity, a method of adhering the metal foil to the surface of the support substrate 11 with a urethane-based adhesive is advantageous.

Next, an etching mask patterned in the shape of the metal wiring portion 13 is formed on the surface of the metal foil of the laminated body. The etching mask is provided so that the wiring pattern forming portion of the metal foil, which will be the metal wiring portion 13 in the future, is prevented from being corroded by the etching solution. The method for forming the etching mask is not particularly limited, and for example, the etching mask may be formed on the surface of the laminated sheet by exposing the photoresist or dry film to light through the photomask and then developing it, or an inkjet printer. An etching mask may be formed on the surface of the laminated sheet by a printing technique such as.

Next, the metal foil in the portion not covered by the etching mask is removed by the dipping solution. As a result, the portion of the metal foil other than the portion that becomes the metal wiring portion 13 is removed.

Finally, an alkaline stripper is used to remove the etching mask. As a result, the etching mask is removed from the surface of the metal wiring portion 13.

(Insulating protective film forming process)
After forming the metal wiring portion, the insulating protective film 14 is laminated and formed. This lamination is not particularly limited as long as it is a coating means capable of uniformly coating the insulating ink, and for example, screen printing, spray coater, phone melt coater, bar coater, applicator, blade coater, knife coater, air knife coater, curtain. Flow coaters, roll coaters, gravure coaters, offset printing, dip coaters, brushing, and all other normal methods can be used. However, among these, the desired surface roughness can be obtained on the surface of the insulating protective film 14 by adjusting the ink viscosity, the screen mesh count (screen hole size), and other printing processing conditions (mainly the speed of plate release). It is preferable to use screen printing which can easily form an arbitrary diffuse reflection surface 141. In particular, when the insulating protective film 14 has a multi-layer structure as described above, it is extremely preferable to form the insulating protective film 14 by a step of applying the insulating ink a plurality of times by screen printing. Further, also when forming a white insulating protective film having a multi-layer structure in which light reflecting layers are separated from each other as shown in FIG. 6, white insulating ink is applied to each layer in a desired pattern. It is preferable to use a manufacturing method of applying by a screen printing method.

Further, in the case of recoating by screen printing in the case where the insulating protective film 14 has a multilayer structure, the coating range of the insulating ink forming the adhesion layer is wider than the coating range of the insulating ink forming the light reflecting layer. Expand to the area close to the outer edge of the LED element 2 (with respect to the coating range of the insulating ink forming the light reflecting layer, to a range of about 0.1 to 0.2 mm in front of it so as not to reach the outer edge of the adhesion layer. (Stop), it is preferable to print each of these layers. By performing the above-mentioned recoating in such an manner, fine leakage from the coating area of the insulating ink forming a light-reflecting layer having a relatively large coating thickness and minute misregistration may occur. It is possible to prevent the LED element mounting area, which should be secured in the optical design, from being eroded.

<Manufacturing method of LED module>
A method of manufacturing an LED module in which the LED element substrate 1, the LED element 2, and the reflective material 15 manufactured by the above manufacturing method are integrated into an LED module will be described.

[LED element mounting process]
The LED element 2 is mounted on the LED element substrate 1 by joining the LED element 2 to the metal wiring portion 13 by soldering. The joining by soldering can be performed by a reflow method or a laser method. In the reflow method, the LED element 2 is mounted on the metal wiring portion 13 via solder, and then the substrate 1 for the LED element is conveyed into the reflow furnace, and hot air having a predetermined temperature is sent to the metal wiring portion 13 in the reflow furnace. This is a method of melting the solder paste by spraying and soldering the LED element 2 to the metal wiring portion 13. The laser method is a method in which the solder is locally heated by a laser and the LED element 2 is soldered to the metal wiring portion 13. The solder bonding of the LED element 2 to the metal wiring portion 13 is preferably performed by laser irradiation from the back surface side of the support substrate 11. As a result, it is possible to more reliably suppress the ignition of the organic component of the solder due to heating and the damage to the base material due to the ignition. In this step, the solder portion 17 is formed at the position shown in FIG. 7.

[Reflective material laminating process]
The reflective material 15 having openings formed in advance on the LED element substrate 1 on which a plurality of LED elements 2 are mounted in a matrix is placed at an appropriate position so that all the openings overlap with the individual LED mounting areas. Perform the process of mounting. When the adhesive layer 16 is formed on the reflective material 15, the reflective material 15 is placed in the same appropriate position with the adhesive layer 16 facing the side of each component of the LED element substrate 1. The reflective material 15 is temporarily attached to the LED element substrate 1.

After the reflective material 15 is placed at an appropriate position on the LED element substrate 1, the pushing film 18 is further placed on the reflective material 15 as shown in FIG. As the pushing film 18, for example, a resin film made of polyethylene terephthalate (PET) or the like, in which the pushing opening is formed at a position corresponding to the opening of the reflective material 15, can be used.

After the pushing film 18 is placed, the entire surface of the pushing film 18 is evenly pressed by a roller or the like to form a resin sheet constituting the reflective material 15 at the peripheral edge of the opening according to the embodiment shown in FIG. A part of the LED element 2 is bent toward the top of the LED element 2 to form the LED element surrounding side wall 151. At this time, the back surface of the reflective material 15 is crimped to the surface of the LED element substrate 1, and at the same time, the inner surface of the side wall 151 surrounding the LED element is crimped to the side surface of the LED element 2. After the LED element surrounding side wall 151 is formed, the pushing film 18 is detached from the LED module 10.

Here, as shown in FIG. 9, the magnitude relationship between the width S3 of the opening of the pushing film 18 used in the pressing process of the reflective material, the outer width S2 of the LED element 2, and the width S1 of the opening of the reflective material is as follows. Set S1 <S2 <S3. The difference between S1 and S2 and the difference between S2 and S3 should be optimized appropriately according to the thickness, bending stress, tensile elongation, etc. of the resin sheet constituting the reflective material, and depending on the presence or absence of the adhesive layer 16. Just do it. For example, when a heat-resistant double-sided tape having a thickness of 20 μm or more and 100 μm is laminated on a polypropylene foam film having a thickness of 50 μm or more and 200 μm and used as a reflective material, S1 is used with respect to the outer width S2 of the LED element. Is in the range of (S2-1200) (μm) or more and (S2-140) (μm) or less, and S3 is in the range of (S2 + 140) (μm) or more (S2 + 5000) (μm). It can be formed in the manner shown in FIG.

When the reflective material 15 does not have the adhesive layer 16, the position and shape of the reflective material 15 are appropriate by fixing the reflective material 15 to an appropriate position by a push rivet or the like after the pushing. Can be held in.

<LED module lighting inspection method>
As described above, as shown in FIGS. 7 and 8, the LED module 10 is a portion of the peripheral edge of the opening of the reflective material 15 that is parallel or substantially parallel to the conduction direction between the pair of conductive plates 131 and 132. Since the LED element surrounding side wall 151 is formed only in the LED module 10, it is visibly exposed in the vicinity of the peripheral edge of the opening by a plan view from the light emitting surface side of the LED module 10. Alternatively, the continuity state of the solder portion 17 can be inspected by a non-destructive inspection in various situations related to subsequent distribution and sales.

<LED display device>
FIG. 10 is a perspective view schematically showing the configuration of an LED display device 100 using the LED module 10 of the present invention. The LED display device 100 includes an LED module 10 and an image display panel 3 such as a liquid crystal display panel. Further, the LED module 10 in this embodiment includes at least an LED element substrate 1, an LED element 2, and a reflective material 15. A reflective material 15 is formed on the outermost surface of the LED element substrate 1 on the light emitting surface side so as to cover a region other than the LED element mounting region for the purpose of improving the light emitting capacity of the LED module 10.

In the LED display device 100, in order to more efficiently radiate the heat radiated from the LED module 10 to the outside, a heat radiating structure 4 made of aluminum or the like is further installed on the back surface side of the LED element substrate 1. preferable. Each of these members is actually fixedly arranged at an appropriate position inside an external frame (not shown) made of metal or the like to form the LED display device 100.

1 LED element board 11 Support board 12 Adhesive layer 13 Metal wiring part 131, 132 Conductive plate 14 Insulating protective film 15 Reflective material 151 LED element surrounding side wall 152 Concave reflective part 153 Notch 16 Adhesive layer 17 Handa part 18 Pushing film 2 LED element 3 Image display panel 4 Heat dissipation structure 10 LED module 100 LED display device

Claims (9)

A board for LED elements in which a metal wiring part is formed on the surface of the support board,
A plurality of LED elements mounted on the metal wiring portion and
An LED module comprising a reflective material laminated on the LED element substrate so as to cover an area other than the LED element mounting area.
The LED element is mounted via a soldering portion on a mounting portion made of a pair of conductive plates which is a part of the metal wiring portion and is formed at positions facing each other so as to be separated from each other.
The reflective material is made of a flexible resin sheet, and an opening is formed at a position corresponding to the mounting region.
A part of the resin sheet bends toward the top of the LED element and stands up at a portion of the peripheral edge of the opening that is parallel or substantially parallel to the conduction direction between the pair of conductive plates. , The LED element surrounding side wall is formed, and at least a part of the inner surface including the top of the LED element surrounding side wall is in contact with the side surface of the LED element.
The LED element surrounding side wall is not formed on the peripheral edge of the opening, which is parallel to or substantially parallel to the direction orthogonal to the conduction direction.
In a plan view from the light emitting surface side of the LED module, a solder portion for fixing the LED element to the metal wiring portion in the vicinity of a portion of the peripheral edge of the opening where the side wall surrounding the LED element is not formed. Is an LED module that is visibly exposed. The LED module according to claim 1, wherein the bending stress of the resin sheet forming the reflective material based on ASTM-D790 is 10 MPa or more and 40 MPa or less. The first or second aspect of the present invention, wherein an adhesive layer is formed on the back surface of the reflective material, and the reflective material is attached to the LED element substrate and the LED element via the adhesive layer. LED module. The LED element surrounding side wall rises substantially perpendicular to the surface of the LED element substrate at the peripheral edge of the opening, and substantially the entire inner surface of the LED element surrounding side wall is on the side surface of the LED element. The LED module according to any one of claims 1 to 3, which is in contact with the LED module. Only a part of the back surface of the LED element surrounding side wall near the top is in contact with a part of the side surface of the LED element near the top, and the LED element surrounding side wall is from the peripheral edge of the opening. The LED module according to any one of claims 1 to 3 , wherein the LED module rises in a tapered shape in which the opening diameter narrows toward the top of the LED element. The LED module according to claim 5, wherein the side wall surrounding the LED element has a concave curved surface shape that is convex toward the support substrate side. The LED module according to any one of claims 1 to 6, wherein the support substrate is a flexible resin film, so that the substrate for an LED element is a flexible substrate. An LED display device including a backlight comprising the LED module according to any one of claims 1 to 7. The lighting inspection method for an LED module according to any one of claims 1 to 7.
The conduction state of the solder portion that is visibly exposed in the vicinity of the peripheral edge of the opening by the plan view from the light emitting surface side of the LED module is inspected without damaging any part of the LED module. A lighting inspection method for an LED module, which includes a process.

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